Greece is almost evenly split over a weekend referendum that could decide its financial fate, with a “Yes” result possibly ahead by a whisker, the latest survey shows.

That is despite warnings that a “No” vote will force the country out of the European Union.

A poll by the Alco institute said 44.8 per cent of Greeks intend to vote yes and 43.4 per cent no – making it the first published survey to give a lead to the yes vote ahead of Sunday’s ballot.

However, the survey had a margin of error of plus or minus 3.1 percentage points, meaning it was still seen as too close to call.

• Why Putin and Obama are keys to a ‘Greek solution’
• Confusion reigns in Greece
• Confused about Greece? Here’s what it all means

The figures nevertheless confirmed other polling results suggesting a swing away from the no vote urged by Greece’s left wing government towards the yes camp.

The Alco survey, carried out on Tuesday and Wednesday this week, after Greece imposed capital controls, found 11.8 per cent of Greeks were undecided ahead of the referendum.

Prime Minister Alexis Tsipras’s government is asking Greece’s voters to vote no to a technically phrased question asking if they are willing to accept more tough austerity conditions from international creditors in exchange for bailout funds.

But EU leaders say the plebiscite is really about whether Greeks want to stay in the eurozone or not.

They add that the question relates to a bailout package that is no longer available to Greece, having expired on Tuesday.

A no in the referendum would not strengthen Athens’ position in talks with its creditors as the Greek government claims, EU Commission deputy president Valdis Dombrovskis said in a German newspaper interview on Friday.

“It would be wrong to think that a no would strengthen Greece’s bargaining position. The opposite is true,” said Dombrovskis, who is the EU’s commissioner for the euro and social dialogue.

The situation for Greece was “substantially worse than it was a week ago” following the shock decision by Prime Minister Alexis Tsipras to call a referendum on the terms of his country’s bailout, Dombrovskis told the daily Die Welt.